Devices for transdermal or percutaneous drug delivery are known, such as described in U.S. Pat. No. Re. 34,692 to Becher; U.S. Pat. No. 2,561,071 to Prisk; U.S. Pat. Nos. 3,598,122 and 3,797,494 and 3,948,262 to Zaffaroni; U.S. Pat. No. 3,923,939 to Baker et al.; U.S. Pat. No. 4,031,894 to Urquhart et al.; U.S. Pat. No. 4,176,664 to Kalish; U.S. Pat. No. 4,379,454 to Campbell; U.S. Pat. No. 4,466,953 to Keith et al.; U.S. Pat. Nos. 4,573,996 and 4,710,191 to Kwiatek et al.; U.S. Pat. No. 4,597,961 to Etscorn; U.S. Pat. No. 4,605,548 to Ushiyama et al.; U.S. Pat. No. 4,638,043 to Szycher et al.; U.S. Pat. Nos. 4,687,481 and 4,810,499 to Nuwayser; U.S. Pat. No. 4,762,124 to Kerch et. al.; U.S. Pat. No. 4,784,857 to Berry et al.; U.S. Pat. No. 4,812,305 to Vocal; U.S. Pat. No. 4,816,258 to Nedberge et al.; U.S. Pat. No. 4,830,854 to Copelan; U.S. Pat. No. 4,830,856 to Peppers; U.S. Pat. No. 4,904,475 to Gale et al.; U.S. Pat. No. 4,917,676 to Heiber et al.; U.S. Pat. No. 5,028,435 to Katz et. al.; U.S. Pat. No. 5,112,618 to Cartmell et al.; U.S. Pat. No. 5,128,137 to Muller et al.; U.S. Pat. No. 5,141,750 to Lee et. al.; U.S. Pat. No. 5,296,222 to Petersen et al.; and WO 96/19205.
Such devices are typically characterized by delivering an amount of a drug, e.g. nitroglycerin, estrogen, estradiol, corticoid, levonorgestrel, etc. to the patient's skin at a rate controlled by the device. Subsequently, the drug is delivered systemically to the intended site of treatment within the body. Although effective for their intended use, such controlled release devices have limited utility for providing the kind of treatment which requires maximum delivery of the drug or active ingredient for local skin conditions, for example, lesions or abnormal skin features such as corns, warts, calluses, bunions, actinic keratoses and hard hyperkeratotic skin as is often found on the face, arms, legs or feet. Other types of delivery devices such as medicated plasters have been used for corns, warts, calluses, etc. However, the amount of active ingredient that can be delivered by such plasters is limited by the dimensions of the plaster and solubility of the active ingredient in the plaster. Consequently, repetitive applications are required for effective treatment. It would be desirable to provide a device which would provide maximum delivery of dermatological ingredients for local skin conditions as described above.